Effects of Connectivity on Ichthyofauna Sampled Through Environmental DNA

• Grant number: 25/05100-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Alexandre Camargo Martensen
• Grantee: Alexandre Peressin
• Supervisor: Elizabeth Anderson
• Host Institution: Centro de Ciências da Natureza (CCN). Universidade Federal de São Carlos (UFSCAR). Campus de Lagoa do Sino. Buri , SP, Brazil
• Institution abroad: Florida International University (FIU), United States
• Associated to the scholarship: 23/17041-3 - Spatial and connectivity analysis for aquatic ecosystems using environmental DNA, BP.PD

Abstract

Connectivity patterns regulate the dispersion of organisms, a crucial process in community structuring. However, freshwater ecosystems have undergone anthropogenic interventions due to the increasing demand for food and climate change-induced expansion of irrigated agriculture, exposing them to rising fragmentation pressure. Recent studies have shown that stream fishes are highly sensitive to changes in connectivity patterns and have difficulties in overcoming even small barriers. In this context, this project aims to evaluate the potential effects of changes in connectivity patterns on the diversity and composition of fish assemblages. It will be done using environmental DNA samples already collected from 75 sampling points of 1st to 5th order streams, representing a gradient of connectivity. Various river connectivity indices will be tested to identify which best explains the observed variability in the assemblage. By understanding the effects of connectivity, this project aims to provide support for the planning of irrigation permits and the restoration of river connectivity. Using the innovative and non-invasive technique of environmental DNA, this project also has the potential to detect species that are difficult to observe. This request aims for an internship, supervised by Dr. Anderson, who investigates anthropogenic effects in tropical freshwater ecosystems across several continents, potentially providing a broad overview, strong background, and internationalization for both the project and the candidate career.